The Mount Sinai School of Medicine (MSSM) proposes to continue a highly successful Cancer Biology training program for predoctoral fellows and expand it to include postdoctoral fellows. This program reflects a major expansion of cancer research at MSSM, which has experienced 10-fold growth in NCI funding over the past 8 years. The training program reflects an integral component of the institution's Cancer Center, in which training mentors play key leadership roles. The program encompasses a laboratory-based, multidisciplinary program in cancer biology. Five predoctoral trainees would continue to be supported by the training program, which has demonstrated the ability to attract and develop a cadre of outstanding PhD and MD/PhD students in cancer focused research. The added postdoctoral training component would initially include 2 fellows and would be closely coordinated with an independent NCl Cancer Biology postdoctoral training grant, which emphasizes training of clinical fellows, expanding training through new, non-overlapping faculty members. The training faculty consists of 36 preceptors from 12 departments and centers throughout Mount Sinai. Of these faculty, 70% have peer-reviewed support from extramural agencies for cancer-related studies. The curriculum for the predoctoral and postdoctoral trainees involves some core elements including advanced course work in both basic and clinical cancer biology. All trainees will participate in regular conferences, which will utilize the superb clinical resources at Mount Sinai and will further expose trainees to clinical aspects of cancer. There will also be specific training elements for each group. The training program includes a rigorous evaluation and selection process for trainees, and the program is both cognizant of and actively involved in minority recruitment. This training program combines research in the biology of cancer with a curriculum that challenges trainees to consider how their research may be translated into improvements in the diagnosis and treatment of cancer. The trainees will work closely with faculty drawn from throughout Mount Sinai ensuring that this research is both comprehensive in scope and related to practical issues faced by physicians in preventing and treating cancer.